Detent mechanism for double hung sash window



April 21, 1959 E. 'r. AKEHURST 2,333,225

DETENT MECHANISM FOR DOUBLE HUNG SASH WINDOW Filed 001:. 16, 1955 I v 5Sheets-Sheet 1 INVENTOR. 52 w/v 7? nun/vest DETENTMECHANISM FOR DOUBLEHUNG SASH WINDOW Filed Oct. 16,1953

April 21, 1959 Eff-[AKEHURST 5 Sheets-Sheet 2 INVENTOR. sew/v 1:azewuns'r;

April 1959 E. T. AKEHURST 2,883,225

DETENT MECHANISM FOR DOUBLE HUNG SASH WINDOW Fild Oct. 16, 1953 5Sheets-Sheet 3 INVENTOR. Eel/11v 7: nzswuesv Patented Apr. 21, 1959DETENT MECHANISM FOR DOUBLE HUNG SASH WINDOW Ervin T. Akehnrst,Baltimore, Md.

Application October 16, 1953, Serial No. 386,466

Claims. (Cl. 292-35) This invention pertains to double hung sash windowoperators and more particularly to a mechanism for raising and loweringconventional vertically moving Sashes.

The present invention constitutes an improvement over the disclosure ofmy prior application, Serial Number 318,418, filed November 3, 1952, nowabandoned, for fWindow Assembly and deviates from the prior disclosureto the extent of disclosing an improved mechanism for locking the sashesin pre-determined positions. In the prior application there is discloseda manually operable pin means which may be retracted or inserted insockets in the window frame through the edges of respective sashes forthe purpose of holding the sashes at various adjusted positions. Inaccordance with the present invention, there is provided a mechanismwhich eliminates the necessity for separate manual operation of detentmeans for the upper sash and which provides an essentially improvedoperation. r A primary object of the present invention, therefore, is toprovide relatively cheap and practical mechanism which willautomatically lock the upper sash at any of a number of pre-determinedpositions, in response to manual release means carried by the lower sashonly.

- It is another object of the present invention to provide a windowoperating mechanism which can be readily adapted to use with presentconventional window frame constructions, and requiring a minimum ofmodification of the frames.

,It is an additional object of the present invention to provide a windowoperating mechanism and detent ele merits which will enable adjustmentof the sashes to any position desired within a large range of selectedpositions. It is still a further object of the present invention toprovide a window mechanism of such a nature that it may be optionallymodified for use with either of two.

types of detents for holding the upper sash in adjusted positions.

Inbrief, the present invention comprises a Worm gear and crankarrangement as hereinbefore disclosed in the aforementioned priorapplication, but wherein the lower sash carries a manually-operablespring biased rod-like element engageable in a notch fashioned in adetent element wherein the notched element is. set at a mid position ofthe window frame so as to hold the lower sash in uppermost position whenso desired. In addition, the notched element is provided with areciprocating pin engageable by the rod-like element so that such pinmay be motivated thereby and whereby a relatively simple mechanism isactuated for the purpose of withdrawing a latching pin from one of aseries of detent notches in the edge of upper sash so as to release theupper sash for motion.

In a modification of the present invention, only the manually operablerod-like member carried by the lower sash in conjunction with thenotched member on the window frameis utilized for holding the lower sashin uppermost position, relying on a novel frictional detent whichengages the edges of the upper sash to hold that sash in any adjustedposition.

Other objects and advantages of the present invention will be apparentfrom the subsequent description and figures of the drawing wherein:

Figure 1 is an elevation of a double sash window incorporating elementsof the present invention, certain portions of the frame being brokenaway to show details of the combination;

Figure 2 is an enlarged section taken generally along the line 2-2 ofFigure 1;

Figure 3 is a section taken generally along the line 3-3 of Figure 2;

Figure 4 is an enlarged perspective of the detent means as applied tothe upper and lower sashes;

Figure 4a is a fragmentary perspective showing the relationship ofcertain elements of Figure 4 in a differ ent position;

Figure 4b shows a portion of a detent element;

Figure 5 is a fragmentary elevation showing the reladetent used Figure 9is a longitudinal section of the detent shown in Figure 7 taken alongline 99 of Figure 8; and

Figure 10 is a section along the line 1010 of Figure 8.

Referring to the figures of the drawing and especially Figures 1 to 5,there is disclosed a window having lower sash 10 and upper sash 14,shown as slidably set in a conventional window frame 18 having a sidepanel 18a and front panel 18b, the frame and panels being best shown inphantom in Figure 4. v 1

For purposes of illustration the lower sash 10 is shown in a partiallyraised position While the upper sash 14 is shown in a partially loweredposition. i j

A crank 20 is journaled in a well known manner in the lower edge 19 ofsash l0 and serves. to rotate a Worm 22 engaging a worm gear 26, whencerotation of a shaft 30 is effected for the purpose of driving a pair ofspur gears 32 and 34 pinned to the shaft (Figure 2). It will beunderstood that the shaft 30 extends from both sides of the worm gear 26and effects rotation of spur gears such as 32 and 34 at both sides ofthe lower sash 10, as.

indicated generally in Figure 1 showing gear racks 38 and 40 at bothsides of the window. it Accordingly, all mechanism on each side of thewin dow being duplicated on the other side, the description,

herein will be discussed for the most part for one side only, e.g., theleft side as shown in Figures 2, 4, 4a and 5.

The gears 32 and 34 are engageable, respectively, with racks 38 and 40,the rack 3-8 being fastened to the frame.

the rack extending somewhat below the lower edge of,

that sash as indicated at 40a.

Accordingly, it will be appreciated that when crank 20 is rotatedsufficiently to bring the lower sashltl toits tipf 1"] Fermi. g. Y

3 permost limit, the gear 32 will pass beyond mesh with rack 38 and gear34 will commence meshing with rack 40. The spacing of the ends of theracks as shown in Figure is such that gear 32 will clear rack 38subsequent to meshing of gear 34 with rack 40 and thereafter a suitabledetent mechanism is effective to hold the lower sash (and gear 32) inproper fixed position for actuation of the upper sash. It will beappreciated, however, that at any point in the travel of the lower sash10, prior to reaching the uppermost position, the friction between worm22 and Worm gear 26 will be sufiicient to hold the lower sash at anyintermediate position, the upper sash 14 remaining fully closed byvirtue of detent means to be hereinafter described.

Referring now to Figure 4, the device for holding the lower sash 10 inuppermost position includes a housing 50 fastened to the bottom edge ofthe lower sash as by flanges 52 screwed thereto.

Slidably arranged within the housing is a rod-like element 54, the innerend of which is bent outwardly to form a handle 56 protruding through aslot 58 in housing 50. Socketed within the housing is a compressionspring 60 which maintains a constant bias of the rod-like detent element54 toward the window frame. The same construction is duplicated on theother, i.e., the right side of sash 10 in that the housing 50 extendsthereacross and a rodlike element 61 (Figure 1) is slidably housedtherein as indicated by another protruding handle 56a and anotherbiasing spring 60a. Thus, it will be understood that the handles 56 and56a may be grasped, pressed, and forced toward each other against theforce of the respective biasing springs so as to draw the outer ends ofthe slidable detent elements inwardly. It will be noted that the handles56 and 56a are located off center of the sash so as not to interferewith the path of motion of crank 20, the slidable elements 54 and 61Within housing 50 being obviously of unequal length.

The outer end of the detent elements 54 and 61 are each provided with aroller, such as the roller 64, which is engageable within a notch 66 ofa detent element 70, riding intothe notch on a cam surface 71 providedas part of element 70. Element 70 is fastened as by bolts 72 to thewindow frame panel 18a. Thus, as seen on Figure 1, the detent element 70at each side of the frame 18 is located substantially midway of thevertical height of the frame.

From the description given thus far it will be understood that the lowersash may be raised by means of the crank 20 until such time as therollers 64 engage the respective sloping cam surfaces 71 at which timethe rods 54 and 61 are forced inwardly against the bias of theirrespective springs 60 until at the uppermost limit of motion therespective rollers 64 snap into the respective notches 66. Thus, anautomatic catch for the lower sash 10 is effected and it will beunderstood that the position of the notch 66 is such that the gear 32substantially clears rack 38at the time the rollers snap into thenotches. Preferably, the notches should be so positioned that it willnot be possible for the gears 32 to grind against the top teeth of therespective racks 38 during the cranking motion and accordingly thenotches 66 should be so located that the final fractional inch of upwardmotion of the lower sash is performed by pinion 34 acting on rackportion 40a to maintain upward motion of sash 10, the sash 14 beingrestrained against motion at that time, thus providing a clearancebetween the periphery of the gear 32 and the rack 38.

At uppermost position of sash 10, gear 34 is in mesh with its rack 40 onupper sash 14 as set forth, which sash 14 is restrained from motionuntil this time by a pin 73 acting in any one of a series of notches 74in the edge of sash 14.

A mechanism is provided actuatable by the movement of rollers 64 intonotches 66 for unlocking upper sash 14. This mechanism has a base plate75 secured to the inner surface of panel 18a by the screws 72, threadedinto the base plate 75 on both sides of the window frame as shown inFigure 4, and comprises a slidable pin having a reciprocal fit within abore of plate 75, and element 70, and biased so as to normally protrudeinto notch 66, being forced back therefrom by roller 64 when the rollersnaps into the notch. The spring 60 will be understood to havesuflicient force on rod 54 to overcome the bias on pin 80.

The pin 80 may be slidably supported within a collar 82 inserted in theframe panel 18a.

The outermost end of the pin 80 is provided with a notch 84 engaged overthe top edge of a lever 86 secured as by welding to a pivotal shaft 87.Lever 86 is provided with an oversize aperture 88 encompassing a pin 90carried by plate 75. As viewed on Figure 4a when pin 80 moves toward theleft, shaft 87 rotates counterclockwise to the position shown in Figure4.

A bias on pin 80 is provided by a spring 98 intermediate.

theplate 75 and the lever 86 and being retained in position by pin 90fixed to the plate 75, serving to bias the lever for clockwise motion asviewed on Figure 4a which shows the position of lever 86 when the uppersash 14 is under restraint. Thus, when the roller 64 engages in notch66, pin 80 will be forced to the left, as shown in Figure 4, therebycausing counterclockwise motion of lever 86.

Shaft 87 is journaled in lugs 102 and 104 suitably secured as by weldingto plate 75. Likewise welded or otherwise suitably fastened to the shaft87 is a lever 106,

the upper edge of which is engaged by a notch of the locking orrestraining pin 73, hereinabove mentioned, which pin is slidably passedthrough plate 75 and frame panel 18a.

The pin 73 is provided with a cam surface 116 as best shown in Figure4b, which engages in the series of apex tures 74 which apertures arepreferably provided in a metal strip 122 fastened to the edge of uppersash 14.

Accordingly, spring 98 acting against lever 86 andthrough shaft 87 andlever 106 serves to maintain pin 73 in position to engage in any of theseries of apertures 74. It will be apparent that pin 80 when pushed byroller 64 will cause rocking of lever 86, shaft 87, and lever 106 topull the end of pin 73 out of any engaged aperture 74 so as to provideunimpeded motion of the sash 14 under the impetus of its driving gear34.

By virtue of the cam surface 116, pin 73 serves as a yieldable restraintand even though the lower sash is only partially raised so that gear 34is not in mesh with rack 40, the upper sash 14 may yet be moved updirectly, by pushing it or pulling it with the hands in a well knownmanner as applied to conventional sashweight type windows, providing thespring 98 is suitably resilient and the cam angle of surface 116 issuitably steep, all deemed a matter of proper design, to permit suchsurface to snap past the aperture edges when sutficient force is appliedto the sash.

Thus, sash 14 can be directly moved to uppermost position from anylowered position whether or not the rack 40 and gear 34 are inengagement. If the rack 40' and gear 34 are in engagement, enough forcemust be exerted to rotate the gear 34 and mechanism associatedtherewith.

This ratchet type arrangement of the cam surface 116 enables the uppersash 14 to be quickly closed if partially open in the event of rain orstorm while at the same time preventing the lowering or opening of thesash except by means of the crank 20. Since the lower sash can also bequickly lowered by manually pushing the handles 56 and 56a together todisengage the roller 64 from the notch 66, it is evident that the lowersash may also be lowered quickly.

In ordinary operation, lower sash 10 may be fully.

raised to locked position and the upper sash 14 then partially or fullylowered solely by continued rotation of crank 20-. The handles 56 maythen be pressed inwardly to release the lower sash, at which time it maybe cranked downwardly to a lower position, or to the lowermost positionleaving the window fully open at the top.

The teeth of the two racks will be approximately aligned for the variouspositions of apertures 74 and Suitable tolerances between the gear teethand rack teeth provided so that no binding effect will be experienced.

From the above description it will be apparent that both sashes may, byvirtue of mechanical cranking, be placed in fully raised position orfully lowered position, or in' any desired individual intermediatepositions, such intermediate positions being effected by raising thelower sash to uppermost position so as to engage gear 34 and rack, 40,automatically disengaging the restraining pin 73, whereupon continuedcranking serves to lower the upper sash.

It is desirable to provide for assembly or removal of the detentmechanism when the side panel 18b is removed along with, the sashes and14 in the manner of conventional window frame construction. To this endthe aperture in lug 104 is provided with a slot 124 while the shaft 87is notched as at 126 on both sides. The pin 90 is provided with a notch128 as shown in Figure 4a. Aperture 88 in lever 86 is slotted as shownat 129. Accordingly, if the lever 86 be grasped it can be forced againstspring 98 to a position where the slot 129 is in register with notch128, and thus pulled away from pin 90. This will cause the notches 126to register with slot 124 while at the same time pulling lever 106 awayfrom engagement with pin 73. Lever 86 is now entirely cleared of pin 80and the sub-assembly comprising the levers and shaft 87 may be liftedupwardly to clear the lug 104, the end of shaft 87 having slid clear oflug 102. The screws 72 may then be removed from the sash side and theplate 106 from the back of the panel 18a.

In the form of the invention shown in Figure 6 through 9 an arrangementis shown of a simplified nature comprising a frictional detent such asthe detent 200 set within the window frame on the side panel 204 andarranged to press against the edge of the upper sash 206. The detent 200comprises a base 210 having flanges 212 which are perforated toaccommodate screws for fastening to the inner surface of the side panel.The base 210 is fashioned from a single piece of metal having a baseportion 216 from which is bent a flange 220 on each side. The ends 224of the flanges are bent at right angles thereto and overlapped as shownon Figure 10, being soldered or welded together.

Ends 224 are slotted as at 228 in register with each other toaccommodate outwardly struck lugs 230 of a frictional element or shoe234 which engages within a groove 243 or rabbeted portion in the sideedge of the sash. The lugs 230 are carried at the ends of inwardly bentflanges 238 and accordingly it will be seen that the member 234 issecured for reciprocal motion with respect to the base 216. The element234 is likewise provided with a pair of pins such as the pins 240 whichserve to center respective springs 242 for hearing against the base 216in such a manner so as to force shoe 234 away from the base. Thus, byproperly positioning a detent 200 on each side of the window frame so asto bear against the side edges of the upper sash, which are rabbeted at243 to accommodate the width of the detents, it will be seen thatfrictional forces may be utilized to maintain the upper sash in anydesired position. It will be appreciated that the length of the surfaceof element 234 is such that it is always in full engagement with theedges of the upper sash regardless of any adjusted position of thatsash. It may be further noted by reference to Figure 9 especially thatthe face of the shoe 234 is not parallel to the base portion 216.

In other words, the shoe 234 has a definite slant relative to the baseportion 216 so that the assembled detent 200 is' Wider or thicker at theleft hand end (as viewed in Figure 9) than at the right hand end. Whenthe detent 200 is mounted on the window frame the thicker end ispreferably uppermost as this tends to render the upper sash 206 harderto lower than to raise and helps keep the upper sash 206 in closedposition during movement of the lower sash 208 by the crank member.

The description of the lower sash and the co-action between the twosashes is thought repetitious, since it would merely duplicate all thathas been heretofore described, it being appreciated that by virtue of anarrangement of gears and racks the lower sash may be raised until itreaches its uppermost position at which point the driving gear for theupper sash meshes with the rack on the upper sash and the upper sash maythen be forced downwardly, the cranking force overcoming the friction ofthedetent elements 200. The upper sash'may be left in any adjustedposition held by virtue of the force exerted by the detent elements 200.Preferably a detent arrangement such as shown by the sliding rods 54 andnotched elements 70 would be utilized in conjunction with the frictionaldetents shown in Figure 6 for the purpose of holding the lower sash inuppermost position so that the gear thereof is maintained clear of itsrack while driv ing the upper sash downwardly; otherwise, the gearof thelower sash would be constantly slipping past the topmost tooth of itsrack and cause wear thereon.

It will be apparent that the arrangement shown in Figure 6 may beutilized to place the sashes in any desired position. The first positionis. obvious, this being the one where both sashes are uppermost; thesecond position will likewise be apparent wherein both sashes arelowermost, this being accomplished by raising the lower sash to theuppermost position then lowering the upper sash to lowermost positionand finally reversing the rotation of the crank to lower the upper sash,it being noted that the two racks will have their teeth aligned for allpractical purposes when the upper sash is in lowermost position toprevent interference. It will, of course, be understood that it is notabsolutely essential that the teeth be aligned perfectly, but such acondition is preferable for effecting a smoothly operating mechanism.However, it should be noted that even :if the teeth are misaligned, thiswould merely cause a slight motion of the upper sash in an upwarddirection to thereby automatically align the teeth. Such motion would,in all probability, be a small fraction of an inch and need not beconsidered seriously, particularly in view of the fact that thelowermost edge of the upper sash would in all probability still notclear above the sill of the window.

Should it be desired to adjust the sashes to intermediate positions, itwould merely be necessary to raise the lowermost sash 208 to theuppermost position, then bring the lower sash down by continued rotationof the crank to any desired position, at which point it will be held bythe detents 200 whereupon the lower sash may then have its motionreversed by reversing the crank and brought downwardly to any desiredposition.

While herein-above stated that it would be preferable to have a lockingdetent for the lower sash it should be apparent that the provision ofsuch :a detent is not absolutely essential, but would serve to preventwear on the lower sash driving gears due to the riding of these gearsagainst the uppermost teeth of the fixed racks while the crank is beingturned with the lower sash in uppermost position to lower the uppersash. By the choice of suitable tooth curvatures and heavy greasing suchwear could be minimized as will be understood by persons skilled in theart.

The form of the invention shown in Figures 6 to 10 may readily beapplied to conventional alreadydnstalled window frames as will beapparent to persons skilled in the art.

I claim:

1. A window comprising a pair of sashes and frame means, detent meanscarried by one of said sashes and comprising a movable latch element, adetent member carried by said frame means and engageable by said latchelement at a pre-determined position of said one sash to lock said onesash, detent means for said other sash comprising a restraining pincarried by said frame means and an aperture in said other sashengageable by said restraining pin, a movable release pin carried bysaid frame means and movable by said latch element when said latchelement engages said detent member, and means intermediate said releasepin and said restraining pin whereby said restraining pinis disengagedfrom said :apertur'e when said release pin is moved by said latchelement.

2. A window as set forth in claim 1, said means intermediate said pinscomprising a rockable shaft journa'led on said frame means, a leversecured to said shaft and engaging said restraining pin, a second leversecured to said shaft and engaging said release pin, and meansresiliently biasing said restraining pin toward restraining engagementwith said aperture.

3. A window as set forth in claim 2, including means for journaling saidshaft on said frame means comprising a lug secured to said frame meansand having .a slot therein comprising a substantially circular portionin which said shaft rests rotatively and being longitudinally slidabletherein, a slot extending from the surface of said lug to said circularportion, said shaft having a reduced portion slidable insaid slot forremoval of said shaft from said lug, saidshaft being normally disposedso that said reduced portion is spaced from said slot whereby said shaftis normally retained in said lug.

4. A window as set forth in claim 3, said pins being provided withnotches, each lever having an edge normally engaged in the notch of arespective pin and being slidably removable with respect thereto whensaid shaft is slid longitudinally with respect to said lug to bring saidreduced portion of said shaft into alignment with the slot in said lug,whereby said shaft and said levers may be integrally removed from saidframe means.

5; A detent mechanism for a window having a pair of sashes .and aframing panel at the side of said sashes, comprising a detent memberhaving a notch therein secured to said panel, a Latch means resilientlybiased toward said notch and being carriedby one of said sashes whereinsaid latch means is engageable with said notch at a pie-determinedposition of said one sash, detent means for restraining motion of saidother saish a ainst its own weight, and means engage'able by said latchmeans and actuated thereby when said latch means is engaged in saidnotch for releasing said latter detent means.

References Cited in the file of this patent UNITED STATES PATENTS832,731 James Oct. 9, 1906 867,911 Buttress Oct. 8, 1907- 919,311Bollbach Apr. 27, 1 909 1,339,879 Cima -1 May 11, 1920 2,256,905 MossSept; 23, 1941 2,575,575 Altwies NOV.- 20, 1951 2,649,301 Signore Aug,18,- 1953 FOREIGN PATENTS 228,350 Great Britain Feb. 5, 1925

